The PR31700 is a 75MHz R3000 (PR3901 Processor Core) with MMU, 4K Instruction / 1K Data cache. PR31700 also contains multi-channel DMA controller, ROM, Flash, RAM, DRAM, SDRAM, SRAM, and PCMCIA controller. It is also identical to the Toshiba 3912 processor from the TX39XX family. It is pretty clear that Philips licensed or bought this core directly from Toshiba.